Overview
This opening chapter invites you back into the world of science and sets the tone for the whole year. It shows that science is not only a set of facts to remember but a way of thinking: noticing things, asking questions, trying them out and checking the answers honestly. You will see how simple things, like a paper plane or a bird's wing, led people to big discoveries such as flight. This year you will ask deeper questions: how things work, why events happen and what patterns nature follows. You will learn by doing, through activities and fair experiments where you predict first and then test. The chapter gives a quick tour of the book, from acids and bases, electric circuits, metals and changes, to heat, water, adolescence, life processes, time, light and the Earth, Moon and Sun, and shows how these branches are connected. It also reminds you that knowing science brings responsibility for the environment and for a sustainable world. Finally, a playful activity turns the usual exam around: you are given answers and must invent creative, testable questions for them.
हिंदी में पढ़ें
विज्ञान प्रश्न पूछने, परखने और जिज्ञासा का एक तरीका है। यह आरंभिक अध्याय वैज्ञानिक की तरह सोचना सिखाता है और पूरे वर्ष की यात्रा की झलक देता है।
Learning Objectives
- Explain that science is a process of asking and testing, not only a set of facts
- Give examples of how simple observations led to big discoveries
- Ask how-, why- and pattern-questions about everyday things
- Describe the steps of a simple investigation and the idea of a fair test
- Name the main areas of science in this book and link two chapters
- Explain why scientific knowledge brings responsibility towards the environment
- Invent creative questions for a given answer and tell testable questions from opinions
- Support a claim with evidence from an observation
Topics in this chapter
7 topics · tap a topic title to jump straight to it.
Science is a way of thinking, not just a list of facts
1Think first
2The idea, in plain words
Fold a sheet of paper into a plane and throw it. Sometimes it glides far, sometimes it dives at once. Most people simply fold another one. A curious person stops and asks: why did that one fly better? That small question is where science begins.
Many of us think science is a big box of facts to be learnt for a test. Facts matter, but they are only the results. Science is a process: a way of looking at the world, asking questions, trying things out and checking the answers. A scientist is not someone who knows everything. A scientist is someone who keeps asking and testing.
Where does science happen? Everywhere. It can be about tiny cells inside a leaf or about the Sun and the stars far away. It can be about the soap you use at home or about water flowing deep under the ground. Nothing is too small, too large, too near or too far to wonder about.
Simple things lead to big ideas. People watched birds for thousands of years and wondered how wings hold them up. Early inventors studied bird wings and made gliders and models. Step by step, careful observation and many experiments led to real aeroplanes. The paper plane in your hand is a tiny model of the same questions that engineers still study today: the shape of the wing, the weight and the way air moves around it.
Habits of a young scientist.
- Curiosity: noticing things and asking about them.
- Openness: being ready to hear an answer you did not expect.
- Patience: trying again when an experiment does not work the first time.
- Honesty: writing down what really happened, not what you hoped would happen.
Not knowing is a good start. In science, saying ‘I do not know yet, let us find out’ is a strength. Every discovery started with somebody who did not know the answer and decided to look for it. This year, you will be invited to explore, not only to memorise.
3Worked example
- Asking why one paper plane flies farther than another.
- Wondering why some fruits taste sour.
- Watching how ice melts in a glass of water and asking what makes it faster or slower.
4Your turn
Which of these best describes science?
5Remember this
Asking deeper questions: how, why and what patterns
1Think first
2The idea, in plain words
In Grade 6 you asked many ‘what’ questions: what is this made of, what does this plant need? This year you will go one step deeper. You will ask how things work, why events happen the way they do, and what patterns we can find in nature.
Three kinds of deeper questions.
| Kind of question | Example | What it looks for |
| How does it work? | How does a torch make light? | The parts and the steps inside a process |
| Why does it happen? | Why does a cut apple turn brown? | The cause behind an effect |
| What is the pattern? | Do all sour foods behave the same way with a test paper? | A rule that fits many cases |
Looking for patterns. A pattern is something that repeats. If you notice that lemon, tamarind and amla all taste sour, you may guess that sour foods share something in common. If you then find that all of them change the colour of a certain test paper in the same way, the pattern becomes stronger. Scientists collect many examples, look for what is common, and then test whether the pattern holds for new examples too.
Patterns can be tested. A pattern is useful only if we check it. Suppose you notice that iron things left outside become brown after rain. Is it the rain, the air, or both? To find out, you must set up a fair test where you change one thing at a time. You will do exactly this kind of test later in this book.
Asking ‘why’ again and again. A good ‘why’ often leads to another ‘why’. Why does ice melt in a glass? Because heat flows into it. Why does heat flow? Where does it come from? Each answer opens a new door. This is how science keeps growing.
To be a wise person, be a ‘whys’ person. The book reminds you of this playful line from last year. It means that wisdom grows from the habit of asking ‘why’ about the things around us, instead of taking them for granted.
3Worked example
- How does a switch turn a lamp on and off?
- Why do some materials make a lamp glow and others do not?
- Is there a pattern in which objects become flat when hammered?
4Your turn
Which is a pattern question?
5Remember this
Learning by doing: activities and experiments
1Think first
2The idea, in plain words
You can read about how to ride a bicycle, but you truly learn only when you sit on one and pedal. Science is the same. This book asks you to step out of the page, and sometimes out of the classroom, and to experience things through activities and experiments.
Activity and experiment. An activity is a task where you observe, collect, sort or make something, such as testing drops of different juices on a paper strip. An experiment is a planned test to answer a question, where you change one thing, keep the other things the same and watch the result.
Steps of a simple investigation.
- Observe: notice something interesting.
- Question: write down what you want to find out.
- Predict: guess what will happen and why.
- Test: do the activity or experiment carefully and safely.
- Record: write your observations in a table.
- Conclude and share: say what you found and discuss it with others.
Predict before you test. Many activities in this book ask you to predict first and observe later. When the result matches your prediction, your idea gets support. When it does not, you have learnt something even more valuable: your idea needs to change.
Results lead to new questions. Even an experiment that seems to confirm what we expected can raise fresh questions. If a lamp glows with a copper wire, will it glow with aluminium? With pencil lead? With salt water? Science moves forward because each answer suggests the next experiment.
Safety first. Many activities say ‘Caution’. Never taste unknown substances, use only cells and batteries for electricity experiments, and do heating or burning only with a teacher or an adult. A good scientist is always a careful scientist.
3Worked example
- Predicting which objects will make a lamp glow, then testing them.
- Recording colour changes of test papers in a table.
- Changing only the amount of water in a test while keeping everything else the same.
4Your turn
In a fair test, how many things should you change at a time?
5Remember this
One connected science: a tour of this year
1Think first
2The idea, in plain words
Your book has chapters that look different: some feel like physics, some like chemistry, some like biology and some like earth science. But nature does not come in separate boxes. An idea from one area often helps us ask questions in another. Let us take a quick tour of the journey ahead.
Materials around us. Why are some fruits sour? What happens to a turmeric stain on a uniform when it is washed with soap? You will test substances to sort them as acidic, basic or neutral.
Electricity and materials. With cells, lamps and wires you will build circuits. Asking which materials let a lamp glow leads to sorting materials, and to the world of metals and non-metals.
Changes. A torch battery runs out, ice melts, fruits ripen and rocks break into pebbles. Some changes can be reversed, others cannot. You will learn to tell physical changes from chemical ones.
Heat and water. Heat flows, whether it melts an ice cube or a glacier. The Sun’s heat lifts water from the seas, which later falls as rain and may seep into the ground far away.
Living things. Your own body changes quickly in the middle-school years: this is adolescence. You will also study the life processes of animals and plants: how they get food, breathe and move materials inside their bodies.
Time, light and space. How do we measure time and speed? How did early people use shadows to tell the time? How do shadows and mirrors work? And how do the movements of the Earth, the Moon and the Sun give us day and night and eclipses?
| Area | Example chapter idea |
| Chemistry | Acids and bases, metals and non-metals, changes |
| Physics | Electric circuits, heat, time and motion, light |
| Biology | Adolescence, life processes in animals and plants |
| Earth and space | Water cycle, Earth, Moon and Sun |
Look for links. The litmus test from the acids chapter helps you check the oxides of metals. The electricity tester helps you sort metals from non-metals. Burning magnesium, met with metals, appears again in the chapter on changes. Watch for these links: they show that science is one connected story.
3Worked example
- The electric tester is used again to sort metals from non-metals.
- Litmus paper from the acids chapter tests the oxide of magnesium.
- Shadows connect timekeeping with eclipses.
4Your turn
Which statement about the branches of science is correct?
5Remember this
Science and responsibility: caring for our planet
1Think first
2The idea, in plain words
When you understand how something works, you also understand how it can be harmed or protected. That is why science is not only about discovery. It is also about responsibility.
Human actions and nature are linked. What people do at home, in farms and in factories affects air, water, soil and living things. A few examples you will meet this year:
- Too much chemical fertiliser can make soil acidic, and plants then grow poorly.
- Untreated factory waste poured into a lake can harm the fish living in it.
- Burning more fuel in vehicles adds more carbon dioxide to the air.
- Iron structures that rust must be repaired or replaced, which costs money and materials.
Science helps find solutions. The same knowledge also gives us ways to act. Acidic soil can be treated with a base such as lime. Acidic waste can be neutralised before it is released. Metals like iron and aluminium can be recycled instead of being thrown away. Painting and oiling iron slows down rusting.
A sustainable world. Living sustainably means meeting our needs today without spoiling things for people and living beings in the future. Science helps us measure problems, test solutions and choose wisely.
Science and society. Scientific knowledge also connects to how we live together: safe use of electricity, healthy habits during adolescence, clean water and good hygiene. A responsible young scientist shares correct knowledge and questions myths that have no evidence behind them.
What you can do. Notice problems around you, ask what causes them, find out what science says, and try small actions: switch off lights not in use, sort waste, save water, and talk about what you learn with family and friends.
3Worked example
- Adding lime to treat acidic farm soil.
- Neutralising acidic factory waste before it reaches a lake.
- Recycling aluminium cans instead of throwing them away.
4Your turn
Which action shows science used responsibly?
5Remember this
Question the answer: learning to ask good questions
1Think first
2The idea, in plain words
In school, you are usually given a question and asked to find the answer. Let us turn that around. Great scientists are known not only for their answers but for the amazing questions they ask. Asking an interesting question is a skill, and it can be practised.
The game. You are given an answer and you must invent a question or a situation that could lead to it. There is no single correct question. The more creative and surprising your question, the better.
An example. Suppose the answer is ‘Just make it half!’ Possible questions could be: ‘How can two friends share one roti fairly?’, ‘My story is too long for the page, what should I do?’, or ‘This song is too long to dance to.’ One short answer fits very different situations.
Try these answers. The book gives answers such as ‘Just add some milk’, ‘Because the cat’s teeth were crooked’, ‘Don’t panic, I have my towel’ and ‘42’. For ‘Just add some milk’, a question could be ‘This tea is too strong, how can I make it lighter?’ or even ‘The red rose extract is too dark to see a colour change, what should I do?’ Avoid the dull, obvious question such as ‘What is 32 + 10?’ for the answer 42. Look for something surprising.
Why this helps.
- It trains you to see one fact from many sides.
- It shows that a question decides what we look for and what we notice.
- It makes you comfortable with open problems that have many possible answers.
- It is fun, and fun keeps curiosity alive.
Good questions in science. A useful science question is one you can test. ‘Is lemon juice nice?’ is a matter of taste. ‘Does lemon juice change the colour of blue litmus paper?’ can be tested by anyone, and everyone should get the same result. Throughout this book, practise turning your wonder into questions that can be tested.
3Worked example
- Answer: 'Just make it half!' Question: 'How can two friends share one roti fairly?'
- Answer: 'Just add some milk.' Question: 'This tea is too strong, what should I do?'
- Testable: 'Does lemon juice turn blue litmus red?'
4Your turn
Which question can be tested by an experiment?
5Remember this
Thinking like a scientist all year
1Think first
2The idea, in plain words
Each chapter of this book builds on what you already know and invites you to think like a scientist. Let us gather the key habits you will use again and again.
1. Observe carefully. Use your senses safely: sight, hearing, touch and smell. Notice small details, like the colour of a paper strip or the sound a coin makes when dropped.
2. Record honestly. Write observations in a table straight away. If a result surprises you, write it anyway. Honest records are the backbone of science.
3. Compare and sort. Sorting things into groups is a powerful tool. You will sort substances into acidic, basic and neutral, materials into conductors and insulators, and changes into physical and chemical.
4. Explain with evidence. When you say something is true, say how you know. ‘This solution is basic because it turned red litmus blue’ is a scientific statement: it gives evidence.
5. Discuss and share. Talk with classmates. Others may have seen something you missed, or may explain it differently. Science grows when people share and check each other’s ideas.
6. Stay curious after the answer. An answer is not the end. Ask what would happen if you changed something.
| Habit | What it sounds like |
| Observe | I noticed that the spoon became hot at the top. |
| Predict | I think the wooden spoon will stay cooler. |
| Evidence | The lamp glowed, so the key conducts electricity. |
| Wonder | What if I use salt water instead? |
Wonder is the heart of it. It is amazing that humans can wonder about the world, from a drop of lemon juice to the shadow of the Earth on the Moon. Keep that sense of wonder alive, and every chapter becomes an adventure.
3Worked example
- Saying 'This is basic because it turned red litmus blue.'
- Sorting materials into conductors and insulators with a tester.
- Asking 'What if I use warm water instead?' after an experiment.
4Your turn
Which statement uses evidence?
5Remember this
Key Concepts
- Science
- A process of exploring the world by asking questions, observing, testing and checking answers.
- Curiosity
- The wish to know more and to ask questions about the things around us.
- Observation
- Noticing and recording something carefully using our senses or instruments.
- Question
- The starting point of an investigation; it decides what we look for.
- Prediction
- A thoughtful guess about what will happen in a test, made before the test.
- Activity
- A task in which we observe, sort, make or try something to learn about it.
- Experiment
- A planned test to answer a question, changing one thing and keeping the rest the same.
- Fair test
- A test in which only one thing is changed so that its effect can be seen clearly.
- Pattern
- Something that repeats in many cases and may point to a general rule.
- Evidence
- An observation or measurement that supports or goes against an idea.
- Testable question
- A question that can be answered by observation or experiment, the same for anyone who checks.
- Recording
- Writing observations honestly, usually in a table, as soon as they are made.
- Interconnected science
- The idea that physics, chemistry, biology and earth science are linked and help each other.
- Responsibility
- Using scientific knowledge carefully to protect people and the environment.
- Sustainability
- Meeting our needs today without spoiling the world for future people and living things.
- Safety caution
- A rule to follow in activities, such as never tasting unknown substances and using only cells for electricity work.
End-of-Chapter Trial Paper & Test Questions
Topic-wise questions to test your understanding of every concept in this chapter.
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Why is science called a process and not just a collection of facts? / विज्ञान को केवल तथ्यों का संग्रह नहीं बल्कि एक प्रक्रिया क्यों कहा जाता है?
Show answer
Science is a way of finding out: we ask questions, observe, test and check, and the facts are only the results of this work. / विज्ञान जानने का एक तरीका है: हम प्रश्न पूछते हैं, अवलोकन करते हैं, परीक्षण करते हैं और जाँचते हैं; तथ्य तो इस काम के केवल परिणाम हैं।
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How did simple observations help people learn to fly? / सरल अवलोकनों ने लोगों को उड़ना सीखने में कैसे मदद की?
Show answer
Early inventors carefully watched bird wings and tested gliders and models, and step by step these experiments led to real aeroplanes. / आरंभिक आविष्कारकों ने पक्षियों के पंखों को ध्यान से देखा और ग्लाइडर व मॉडल बनाकर परखे; धीरे-धीरे इन्हीं प्रयोगों से असली हवाई जहाज़ बने।
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Give one example each of a how-question and a why-question. / ‘कैसे’ वाले प्रश्न और ‘क्यों’ वाले प्रश्न का एक-एक उदाहरण दीजिए।
Show answer
A how-question is 'How does a switch turn a lamp on?' and a why-question is 'Why does a cut apple turn brown?'. / ‘कैसे’ वाला प्रश्न है ‘स्विच लैंप को कैसे जलाता है?’ और ‘क्यों’ वाला प्रश्न है ‘कटा हुआ सेब भूरा क्यों हो जाता है?’।
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What is a fair test? / निष्पक्ष परीक्षण क्या है?
Show answer
A fair test is an experiment in which only one thing is changed and everything else is kept the same, so that we know what caused the result. / निष्पक्ष परीक्षण वह प्रयोग है जिसमें केवल एक चीज़ बदली जाती है और बाकी सब समान रखा जाता है, ताकि पता चले कि परिणाम किस कारण से आया।
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Why should we predict before doing an activity? / किसी गतिविधि से पहले अनुमान क्यों लगाना चाहिए?
Show answer
Predicting first makes us think about our idea; if the result differs from the prediction, we learn that our idea needs to change. / पहले अनुमान लगाने से हम अपने विचार पर सोचते हैं; यदि परिणाम अनुमान से अलग हो, तो हमें पता चलता है कि विचार बदलना होगा।
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Name the four main areas of science in this book with one example each. / इस पुस्तक में विज्ञान के चार मुख्य क्षेत्रों के नाम एक-एक उदाहरण सहित बताइए।
Show answer
Chemistry (acids and bases), physics (electric circuits), biology (adolescence) and earth science (the water cycle, Earth, Moon and Sun) are the four areas. / रसायन विज्ञान (अम्ल और क्षारक), भौतिकी (विद्युत परिपथ), जीव विज्ञान (किशोरावस्था) और पृथ्वी विज्ञान (जल चक्र, पृथ्वी, चंद्रमा और सूर्य) चार क्षेत्र हैं।
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How are human activities linked to the natural world? Give an example. / मानव गतिविधियाँ प्राकृतिक संसार से कैसे जुड़ी हैं? उदाहरण दीजिए।
Show answer
What people do changes air, water and soil; for example, untreated acidic factory waste in a lake can harm the fish living there. / लोग जो करते हैं उससे वायु, जल और मिट्टी बदलती है; उदाहरण के लिए, झील में डाला गया बिना उपचारित अम्लीय औद्योगिक अपशिष्ट वहाँ की मछलियों को हानि पहुँचा सकता है।
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Suggest a creative question for the answer 'Just add some milk'. / उत्तर ‘बस थोड़ा दूध मिला दो’ के लिए एक रचनात्मक प्रश्न सुझाइए।
Show answer
One creative question is 'My tea is far too strong and bitter, how can I make it lighter?', and many other questions are possible. / एक रचनात्मक प्रश्न है ‘मेरी चाय बहुत तेज़ और कड़वी है, इसे हल्का कैसे करूँ?’; इसके अलावा और भी कई प्रश्न हो सकते हैं।
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What makes a question testable in science? / विज्ञान में कोई प्रश्न परखने योग्य कब होता है?
Show answer
A question is testable when it can be answered by observation or experiment and anyone who checks gets the same result, unlike a matter of opinion. / कोई प्रश्न तब परखने योग्य है जब उसका उत्तर अवलोकन या प्रयोग से मिल सके और जाँचने वाले हर व्यक्ति को वही परिणाम मिले, राय वाले प्रश्नों की तरह नहीं।
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Why should an experiment that confirms our idea still lead to more questions? / जो प्रयोग हमारे विचार की पुष्टि करे, उससे भी नए प्रश्न क्यों उठने चाहिए?
Show answer
Each result shows only one case, so we ask what happens if we change something, and these new questions keep science growing. / हर परिणाम केवल एक स्थिति दिखाता है, इसलिए हम पूछते हैं कि कुछ बदलने पर क्या होगा; यही नए प्रश्न विज्ञान को आगे बढ़ाते हैं।
Related Laws & Principles
Explore allFoundational laws & principles behind this chapter. Each one opens a full page — what it says, why it matters, five practice questions and the mistakes to avoid.